Power transmission mechanism



March 21, 1939. H. THOMA POWER TRANSMISSION MECHANISM Filed May 11, 19558 Sheets-Sheet 1 61/7 BY 4 Q. ATTORNEY March 21, 1939. H. THOMA POWERTRANSMISSION MECHANISM 8 Sheets-Sheet 2 Filed May 11, 1935 INVENTOR' 1H/m J 77/0/19. BY Q ATTORNEY March 21, 1939. H. THOMA 2,150,950

POWER TRANSMISSION MECHANISM Filed May 11, 1955 8 Sheets-Sheet 3 I I lawn v 78 40 40 a a ATTORNEY March 21, 1939.

H. THOMA POWER TRANSMI S S ION MECHANI SM Filed May 11, 1955 8Sheets-Sheet 4 INVENTOR 6494 77/0/ ATTORNEY March 21, 1939. H. THOMAPOWER TRANSMISSION MECHANISM Filed May, 11, 1935 8 Sheets-Sheet 5 R O NE V m H /ys 790m? ATTORNEY March 21, 1939. H THOMA 2,150,950

POWER TRANSMI S S I ON MECHANI S M Filed May 11, 1935 8 Sheets-Sheet '7QUTCHZ I BYd E ATTORNEY March 21, 1939. THOMA 2,150,950

POWER TRANSMISSION MECHANISM 70 I75 /40 j I ATTORNEY Patented Mar. 21,1939 UNITED STATES PATENT OFFICE Application May 11, 1935, SerialNo.21,001 In Germany April 6, 1934 10 Claims. (Cl. 74-262) This inventionrelates to power transmission mechanisms and particularly tohydraulically controlled variable speed transmissions.

One of the objects of the invention is to provide novel and eiiicientmeans for changing the ratio between the speed of revolution of adriving or power input member and that of a driven or power outputmember.

Another object of the invention is to provide hydraulically actuatedmeans for effecting changes in the speed and power ratio between thepower input and output shafts of a device.

A further object of the invention is to provide hydraulic meansincluding a. valve member for selectively varying the speed and powerratio between input and output shafts.

Another object of the invention is to provide a device providing fourforward speeds and a reverse by means of a variably controlled planetaryor epicyclic train of gears interposed between a driving member anda-driven member.

In accordance with one form of the invention a novel form of clutchingmechanism is provided which is smooth and yet effective in its actionand therefore another object of the invention is to provide a novel typeof clutch mechanism which while adapted for use in the present inventionis capable of universal application.

These and other objects and features of the invention will appear fromthe following description of one embodiment thereof which has beenchosen for the purpose of illustrating the principles of the invention.In the drawings:

Fig. 1 is a vertical sectional view through a typical form oftransmission mechanism in which the present invention is embodied.

Figs. 2, 3, 4, 5 and 6 are transverse sectional views of theconstruction illustrated in Fig. 1 taken on the lines 22, 33, etc.,thereof.

Figs. 7. 8 and 9 are detailed sectional views of certain of the featuresof the form of clutch mechanism embodied in the construction of Fi 1;

Fig. 10 is a transverse sectional view taken on the line Ill-I of Fig. 1and showing certain additional features of the construction notillustrated in Fig. 1.

Fig. 11 is a horizontal sectional view of the construction illustratedinFig. 10 taken on the line lI--l l.

Figs. 12A, 12B, 12C, and 12D represent a sectional view taken on theline 1 2-12 of Fig. 10 with the valve mechanism respectively in four ofits possible positions of movement.

Fi 13 is a horizontal sectional view taken on the line l3-l3 of Fig. 10.

Fig. 14 is a sectional view taken on the line ll--ll of Fig. 1illustrating a typical form of silent ratchet mechanism adapted for useas a one way clutch.

Fig. 15 is a sectional view of the construction of Fig. 14 taken atright angles to said figure.

Figs. 16 and 17 are sectional views corresponding to Figs. 14 and 15respectively of altemative' forms of silent ratchet mechanism.

Figs. 18 and 19 are sectional views corresponding to Figs. 14 andrespectively of further alternative forms of silent .ratchetconstruction adapted for use in the present invention. 15

Fig. 20 is a diagrammatic illustration partly'in elevation of a typicalarrangement of hydraulic control mechanism for actuating a change speedtransmission of the type illustrated in Fig. 1.

Figs. 21 to 24 inclusive illustrate alternative positions of the valvemechanism shown in Fig. 20 for use in controlling the mechanism of Fig.1.

Figs. 25 and 26 are diagrammatic illustrations of additional elements ofthe hydraulic system in various alternative positions.

In that form of the invention illustrated in the drawings andhereinafter described there is a driving member such as the power inputshaft A on the left hand side of Fig. 1 which may be connected toaninternal combustion engine, steam 30 engine, motor, turbine, or anyother device from which power is to be taken. The driven member may beany desired element or mechanism for receiving power and as shown at theright hand side of Fig. 1 is in the form of a power output shaft B. Anintermediate clutch controlled shaft 14 is positioned between the inputshaft A and the output shaft B and is provided with a housing. l6,driven thereby as by web I61, within which housing is located a clusterof planetary or epicyclic gears mounted on shafts IS, the ends of whichare supported by the housing. The gears 20' of said cluster engage witha gear 22 on the output shaft B and serve to transmit power fordriving,the shaft in either a forwarder reverse direction. In the followingdescription the term forward is used in referring to rotation in aclockwise direction as seen from the left hand side of Fig. 1, whereasthe term reverse" is used in referring to rotation in acounter-clockwise direction as seen from the left of Fig. 1.

A tubular clutch controlled shaft 24 loosely surrounds the intermediateshaft I4 and is formed at its right hand end with a gear 26 meshing witha gear 28 formed integral with or secured to the gear 20.

omen mechanism is provided at the left ma end of each of the shafts l4and 24 by means of which either or both shafts may be caused to rotatewith the power input shaft A by suitable selective operations. While anysuitable form of clutch mechanism may be employed for this purpose, Iprefer to use two separate clutch constructions of a novel type andwhich are preferably hydraulically controlled. q

Attempts made heretofore to produce a clutch (or brake mechanism)comprising relatively movable members whereby torque is transmitted fromone member to the other initially purely as shear stresses in a fluidsuch as oil have not met with success. The difficulty has been that whenthe members have been moved apart for disengaging the clutch, aconsiderable amount of torque was transmitted by the oil particularly athigh relative. speeds, resulting in a creeping of the driven shaft. whenthe clutch area was reduced or a much thinner fluid used to overcomethis dimculty the smooth gradual engagement possible of accomplishmentthrough taking advantage of shear stresses in an oil film were notsecured but, instead, a rather harsh, sudden, clutch action resulted,particularly as such surfaces cannot be formed with the necessaryaccuracy. I

To overcome these difllculties the present invention involves means forproviding a supply of oil between the clutch elements at the time whenthe clutch is to be engaged and to provide for the draining away of said011 when the clutch members are disengaged. Furthermore, oil from thesame source may be conveniently used to actuate the movement toward andfrom each other of the said clutch members. This construction provides aclutch (or brake) havin a very smooth action and which at the same timeis free from creep when disengaged.

Such a clutch mechanism is shown in detail in Figs. 1, and 4-9inclusive, and since the same construction is used ineach of theclutches C and D which serve to connect the input shaft A with theintermediate shaft l4 and tubular shaft 24, respectively, only one ofthese clutches is described in detail. As shown, the clutch is locatedwithin a housing 36 carried by the input shaft A and rotatabletherewith. A series of annular ,plates 38 are loosely spaced andarranged upon bolts 48 secured to the housing 86. The ring 42 adjacentplates 88 is provided with pistons 44 located on the opposite side ofthe ring and within chambers 46 formed in a recessed ringshaped frame 48rotatable with and extending inwardly from the housing 38. The plates 38are rotatable with the housing and: input shaft but are movable axiallywith respect thereto by means of the pistons 44 under the action offluid supply to the chambers 48 through annular channel 58 in the frame48. f

A similar series of plates 52 is loosely secured by bolts 54 carried bya web or spider 58 keyed to the intermediate shaft l4. The plates 52.are located between the plates 88 and overlap the plates 38 throughouta portion 7 of their area. Slots 58 (see Fig. 4) extend radially in theoverlapping portions of one of said sets of plates, such as plates 52,and are preferably formed with beveled or inclined faces 88 adjacent theedges of the slots. These beveled faces are shown greatly exaggerated inFigs. 4 and 9. 0n relative rotation of the plates the beveled edgesserve to draw oil or other liquid or fluid employed (due to itsviscosity) into the spaces between the surfaces thereof so that thesesurfaces are lubricated anda cushioning of present between the. 7

same prior to actual engagement of the plates which serves throughshearstresses'to produce a smooth gradual clutch application. However,the application of suitable pressure to the pistons 44 serves togradually force the plates 28 into direct contact with the plates 52whereby the shaft I4 is caused to rotate with the power input shaft A.

The, clutch D between the gear operating shaft 24 and the housing 28 isof a like construction and is actuated by pistons 82 shown in the lowerportion of Fig. 1 for forcing the plates 88' of the clutch to the rightinto engagement with the plates 52' carried by the web 84 secured tothe,

gear operating shaft 24.

Any suitable number and arrangement of the as oil from the lubricatingsystem to annular channels 14 and 16 within the ring. As shown in Fig.6, the conduit "connects with the inner channel 14 for actuating theclutch C, whereas the conduit 12 supplies oil or fluid to the outerchannel 18 for actuating clutch D. Refen-ing to Figs. 1 and 5, a channel18 preferably formed in the wall of the rotatable housing 38 connectswith the channel 14 through one or more openings 88 in the outer face.of the housing. The passage 18 extends radially to a tubular member 82passing through slots in the outer edge of the plates 38 of the clutchD. Oil is thus passed to the annular channel or recess 58 in the frame48 from which it is supplied to chambers 46 for urging pistons 44 to theleft as seen in Fig. 1. The plates 88 are thus pressed into frictionalengagement with the plates 52 of the clutch C, thereby connecting theintermediate shaft l4 to the power input shaft A so that they rotatetogether. At the same time oil is-passed from the recess 58 through thepassages 84 (which are preferably throttling passages of small area)into the space about the plates 38 and 52 so that the surfaces of theplates are lubricated and the cushioning action of the oil between theplates is secured. Part of the oil is forced into slots 58 (Figs. 4 and9) and by means -of beveled edges 88 spread between the coactingsurfaces. 'The plates and casing are rotatable so that oil is suppliedto all parts thereof and any excess oil is allowed'to pass back intogrime transmission casing through outlet openings In a like manner, afluid or oil for actuating the clutch D is supplied through the conduit12, annular channel 18, and passages 88 in the outer face of the housing38, to passages 88 extending radially in the walls of the housing andcommunicating at their outer end with tubular members 82 whichcommunicate with recess or annular channel 94 within the frame 48 forsupplying oil under pressure to the chambers 48' for urging the pistons82 of the clutch D to the right, whereby the, plates 38* are moved intoengagement with the plates 52' and the tubular shaft 24 is caused torotate with the driving shaft A. Oil is supplied to the spaces about theplates 38" and 52' through throttling passage 84' and the excess thereofpasses out of the housing through outlet openings 96.

The rings 42 and 42 of the clutches C and D (see Fig. 7) are drawntoward each other by the springs 90 which urge the rings toward theframe 48 so that when the oil pressure applied to the pistons of eitheror both clutches is relieved, the springs cause the rings to move backinto engagement with the frame 48, and the plates 30 and 38' to bedisengaged from plates 52 and 52 to release the clutch Simultaneouslywith the disengagement of the clutch plates the oil about the same isdischarged from the housing through radially extending passages 95 (seeFig. 8) by movement of a spring pressed closure member 91 which isretracted by a member 99 carried by the ring 42 when the ring movestoward the frame 48. On movement of the ring away from the frame, due tothe action of the pistons in causing the clutch plates to becomeengaged, the closure member 91 is moved into position to close thepassages 95 so that oil will be retained in the housing 36. Similardrainage valves are provided for operation by plate 42' for permittingthe escape of oil from clutch D.

The clutch construction described has the advantage of smoothness inoperation. The oil films produced by the beveled edges of the slots inthe plates 52 and 52 serve as a cushion between the plates duringrelative movement thereof and before the plates are forced into directcontact and serve to transmit torque through shear in the film. Theelements of the clutch and of the transmission mechanism are. therebysaved from shocks or impacts between relatively moving parts of themechanism. Furthermore, since the device is continuously supplied withoil or fluid under pressure which flows between the plates and-incontact with the surfaces thereof and flows away through the overflowopenings 86 and 96, any heat generated by friction or otherwise duringoperation of the clutch is carried away by the oil and overheating ofthe elements is thereby avoided.

In order to effect the desired change in ratio of speed and powerbetween the driving member or power input shaft A and the driven memberor power output shaft B, the intermediate shaft I4 and tubular shaft 24are each provided with one way clutches which serve during normaloperation to prevent rotation thereof in areverse direction. Theseclutches preferably operate silently and may be a novel type of ratchetconstruction such'as the threealternative constructions illustrated inFigs. 14 and 15, 16 and 17, and 18 and 19. The one way clutch for attimes preventing rotation of shaft I4 and housing I6 is generallydesignated by the letter F and the corresponding mechanism efi'ectiveupon the tubular shaft 24 is generally designated E. The constructionshown in Figs. 14 and 15 is also shown in Figs. 1 and 10 as applied tothe intermediate shaft I4 (one way clutch device F} while theconstruction of Figs. 16 and 17 is shown as applied to the tubular shaft24 in Fig. 1 (one way clutch device E).

' I In the construction of Figs. 14 and 15 the por-v is connected to anarm I 08 for holding the pawl in its raised position and other end ofwhich is connected to a friction member such as the band IIO whichpasses around on the portion IOI and is attached to the pawl I02 at thepoint I I4 The operation of the device is as follows: On rotation of theshaft I4, housing I6, the portion IOI and the ratchet member I00 in aforward direction, as seen in Fig. 14, the band IIO tends to move withthe shaft placing spring I06 under tension and causing the opposite endof the band to raise the pawl by movement of the point II4 to the right;However, when the shaft begins to rotate in a reverse direction or is atrest, the spring I06 contracts, drawing the band H0 and the point I I4to the left so that the pawl engages the ratchet member and preventsfurther reverse rotation of the shaft.

As hereafter described there are some instances discussed hereinafter,when it is desirable to permit the shaft I4 to rotate in a reversedirection. In such cases the pawl I02 is held in its raised position asby a projection II6 on a slide IIO which is movable into engagement witha rearwardly extending a'rm I20 movable with the pawl.

The one way clutch mechanism of Figs. 16 and 17 is applied to thetubular shaft 24 and embodies a similar ratchet member I00, pawl I02,

and collar 2'. This mechanism may be of the type shown in Figs. 14 and15 or any other constructions such as that of Figs. 16 and 17 or 18 and19. Referring to Figs. 16 and 17, the pawl is normally urged intoengagement with the ratchet member by a spring I22 and may be moved outof engagement by a friction member in the form of a springpressedelement I 24 movable in a guide in arm I26. which is connectedfor rotation with the pawl I02.

The operation. of the device is similar to that of Figs. 14 and 15. Theelement I24 and arm I26 are moved to the right when the shaft 24 rotatesin a forward direction raising the pawl I02 and permitting the shaft torotatefreely. However,

' when the shaft rotates in the reverse direction the spring pressedelement I24 which is in en-- gagement with the collar H2 is urged to theleft therewith rotating the arm and bringing the pawl I02 intoengagement with the ratchet member I00. In a similar way, the pawl I02may be held in its raised position by means of a second projection 6'(see Fig. 1) on slide II8 which when moved-to the left, as seen in Fig.17, depresses the arm I20 and holds the pawl out of engagement with theratchet member.

The construction-of Figs. 18 and 19 is somewhat similar to that of Figs.14 and 15 in that the shaft I4" is provided with a ratchet member I00",pawl I02" and collar II2", as well as a band IIO" which, when carried bythe shaft in a forward direction, causes the pawl to be raised. However,this movement of the band in the construction of Fig. 18 reduces thetension on the spring I2I. Rotation of the shaft in a reverse directionthen tends to increase the tension on the band so that the band travelswith the shaft moving the element l2 4" to the left and bringing thepawl into engagement with the ratchet member I00". Reverse rotation ofthe shaft is thus prevented while forward rotation takes place freely.The pawl may be held,in its raised posi- 1 tion as in thepreviousconstructions by projection While the mechanism above described servesto provide a neutral and three forward speeds, the mechanism may also beprovided with an extra very low speed (low-low speed) and with a reverseby the useof a member I25 which is loosely mounted on the output shaftB. The member is formed on its left hand end as seen in Fig. 1 with gearteeth I23 which may extend into thehousing I3 and mesh with gears I23which are secured for rotation to the planetary gears 23 and 23. Ihemember I25 is shlftable axially by means of an arm I30 e a collar I3I onthe right hand end thereof. Lugs I33 are also provided on the memberI25. for engagement with internal lugs on web I35 secured to thetransmission casing to prevent-rotation of member I25 when its gearteeth I25 are moved into engagement with the gears I23 in the housingI6.

The arm I33 may be carried by a slide I32 which also serves to actuatethe slide I13 by which the pawl actuating projections lit and iii arecarried. The slide I32 is moved from one position to another by suitablemeans such asarotatablecam I34 showninFigs. 1 andll which aroller I36fixedly secured to the slide for movement therewith. Rotation of the lcam I34 is effected by means of a rotatable shaft I38 (Fig. which alsoserves to operate a control element or plug valve I" of the hydraulicsystem by which 011 is supplied to the conduits I0 and I2.

The mechanism described above serves to provide transmission ratiosreferred to as low, intermediate, direct, low-low, and reverse, and thecondition of the clutches C and D, one way clutches E and F, theposition of slldable gear member I25, and the gear ratio obtained isventedbymeanssuchastheoneway'clutchl 'as Intermediate gear ratios-Whenan intermediatespeedisdesiredthechrtchDisreleaseda-ndthe clutch C isengagedby relieving the pressure on the fluid supplied by conduit I2 andapplying pressure to the, fluid supplied by conduit I3 through thechannels communicating with the chambers 35 within which the pistons 44of the clutch C are located.- The clutch C is thus engaged and theclutch Dreleased. The intermediate shaft I4 is thus caused to rotatewith the power input shaft A and the housing 35. The housing I 5 andplanetary gears 23 are also retated with the power input shaft and shaftI4 in a forward direction. The one way clutch device E serves to preventreverse rotation of the tubular shaft 24 and gear 25 and the poweroutput shaft B will therefore be driven through the planetary gears 23and the gear 22 on the left hand end of the power output shaft. With thenumber of teeth in the various gears as given above the gear ratiobetwen the input shaft and the output shaft will be 1% to 1.

Direct gemz-In order to provide a high speed or direct drive both theclutches Cand D are engaged so that shafts II and 24 both rotate withthe housing 35 and the power input shaft A. The planetary gears aretherefore held stashown in the following table: Y tionary upon theirshafts and the gear 22 on the 01m One way clutches f g Ratio 7 NeutraL 0F effective 5 b n na by frictiondavice" a 1 r 1 0 20 V! Intermedlate D mgig v w Ineflective 1 to 1 Oil y 0H g ge s g}; {riotion Lg: w" 111mm" 42 to 1 6 118 on 5 6i... g 1 on: lay lug on 1 5 4 to 1 0 on y 118011 0-.-r held out byslide. (rcversely) (The drive ratios given above are on theassumption that gear has 15 teeth, gear 28 has teeth, gear 25 has l8teeth, gear 22 has 27 teeth, gear I23 has 21 teeth, and gear I25 has I24 teeth.)

. Neutral.-When clutches C and D are not actuated no energy can betransmitted and the device is in neurtal position irrespective of theadjustment of the one way clutches E and F or the slida'ble gear memberI25.

Low gear ratio.--When low forward speed is desired, the clutch Dls'engaged by supplying oil under pressure to the conduit 12, channelsI5, passage 93 and tubular member 92 to the piston 62 within the chamber45'; The plates 52' of the clutch member are thus urged into engagementwith the plates 33 of the clutch member and the tubular shaft 24 istherefore gradually caused to rotate with the input shaft A and housing35. The gear 25 is thus rotated, driving the gears 28 and gears 20 onshafts I8. Reverse rotation of the shaft I4 and housing It is prepoweroutput shaft is driven thereby at the same speed as the power inputshaft, thusgiving a one to one ratio. It will be noted that in directgear ratio none of the gears moves relative to other The gears I28therefore rotate withthe planetary gears 20 while the gear teeth I25 ofmember I25 are held against rotation bythe lugs I33 engaging the web I35secured to the transmission casing. The movement of the slide I32 alsoserves to carry the slide II 8 and the projections H5 and H5 forwardlyinto engagement with the arms I20 on both of the pawls I52 and I02 ofthe one way clutch devices E and F which are normally aiaopco appliedto..the shafts I4 and 24. These shafts are therefore free to rotaterearwardly. In order to procure the low-low gear ratio the clutch C isenergized whereas the clutch D remains disengaged.

With this arrangement of the elements the power input shaft whichrotates forwardly carries the intermediate shaft I4, housing I6, andplanetary gears therewith at the same speed. The

gear teeth I26 which engage gear I28 are locked against rotation asdescribed above, so that the planetary gear I28 rolls around the gearteeth I26 while the gear 20 rolls around the gear 22 on the outputshaft. Due to the difference in number of teeth I26 on the member I andthe gear 22, power is applied to the output shaft in a forward directionat a greatly reduced speed (4.2to1). 4

During the operation above described, the gear 28 causes gear 26 and thetubular shaft 24 to rotate in the reverse direction which is permittedsince the pawl I02 is heldin its raised ineffective position by lugII6'.

Reverse.In providing reverse with the mechanism described the clutch Cis released and the clutch D is engaged. The cam I34v and shaft I38 havebeen previously suitably rotated by movement of hand lever I83 to bringthe gear teeth I26 into engagement with the gear I28 within the housingI6 and to release the one way clutch devices E and F applied to shaftsI4 and 24 to allow reverse rotation thereof. The shaft 24 and gear 26are thus carried in a forward direction while the gear teeth I26 remainstationarycausing the planetary gears to rotate upon their shafts I8,the gears I28 being caused to roll about the gear teeth I26, driving thepower output shaft in the reverse direction at the low gear ratio of 5.4to 1. The housing I6 and shaft I4 are also driven in the reversedirection but since the one way clutch F is held disengaged the partscan rotate without interference.

In the construction of Fig. 1 the mechanism is also provided with ahydraulically actuated brake shown at the right hand side of Fig. 1. Thebrake is shown as similar in form and construction to the clutch devicesC and D. Plates I42 are carried by bolts I43 and cooperate with a ringI44 non-rotatably supported by the transmission casing 68 but movableaxially by pistons I46 to engage plates I48 carried by a web I50 securedto and rotatable with the power output shaft B.

Operation of the brake is eifected by supplying oil or "other fluidunder pressure throughthe line I52 to the annular channel I54 under thecontrol of a foot operated member I56 shown in Fig. 20. p The brakefunctions in the same manner as the clutches C and D to bring the platesI42 smoothly into frictional engagement and direct contact with theplates I48 rotatable with the output shaft. The braking force is appliedover a very large area spaced a substantial distance from the axis ofrotation so that effective braking action is obtained even whenrelatively low pressure is exerted by the oil supplied to the mecha-'nism. WhiIe'the brake is being used a certain amount of oil is permittedto flow through open ing I46 from the actuating cylinders to the brakeplates and thence back into the sump, which oil serves to carry away theheat generated during the braking operation.

The same clutch arrangement can be utilized as a manually operated asdistinguished from a manually controlled brake by the construction shownin dotted lines in Fig. 20 wherein I5I1 is a cylinder within whichoperates the piston I62: operated by the foot pedal I623. When thisconstruction is used the openings I48 are preferably omitted.

The mechanism employed for supplying oil under pressure to the clutchmechanism and to other elements of the device may be ofany suitablecharacter or design, but, as illustrated in Figs. 20 to 25 inclusive,the flow of oil under pressure may be readily controlled by a valveoperable to selectively supply the oil as desired. In the constructionshown in Fig. 20, oil is drawn from a sump I60 by means of a gear pumpor the like I62 and is supplied under pressure through a pipe I64 to asupply line I 66. A relief valve I 64' is preferably utilized to preventexcessive pressure under certain conditions. The pump I62 may be thesame as that used to supply oil for lubrication to the engine or otherdevice and for this purpose a pipe I65 is provided which communicateswith the pipe I64 and extends to the usual lubricating system.

The supply line I66 leads to a valve I68 .provided with a chamber I10within which a valve member I 12 is slidable. The inner face of thechamber is provided with suitable ports to which are connected thesupply line I66, relief lines I14 and I16, and pressure lines 10' and12' which extend through passages I15 and I11 in the control element Ito the conduits 10 and 12 for oil under pressure is passed by the supplyline to the valve chamber I10. The upper recess I18 providescommunication between the supply line and the ports to which the reliefline I14 and pressure line 10' are connected. Therefore, since therelief line I14 is not sealed, oil flows freely through the chamber I10to the relief line I14 and back to the sump and pressure is not appliedto the pressure line 10'. The clutches therefore are not actuated andthe transmission remains disengaged or in neutral.

When the valve I12 is movedupward to the position of Fig. 22 the supplyline I66 is brought into communication with the pressure line 12' bythe'recess I80 in the valve so that oil under pressure passes directlyto the pressure line and thence through the control element I40 to thepipe 12 and the clutch 'D. The clutch D is therefore actuated and thetubular shaft 24 is caused to rotate with the power input shaft A todrive the power output shaft in low gear.

When the slide I12 is raised to the position shown in Fig. 23 the recessI80 thereof provides communication between the supply line I66 andpressure line 10 so that oil under pressure is supplied through controlelement I40 to the conduit 10 for actuating the clutch 0. At the sametime the pressure line 12' is brought into communication with the reliefline I16 by the recess I82 so that the pressure on conduit 12 isrelieved. When in this position the clutch C is brought into engagementwhereas the clutch D is released and the power output shaft is thereforedriven at intermediate speed as described more fully above.

. in Fig. 21 wherein oil passes therethrough directly from the pressurelines 10' and 12 to the conduits 10 and 12 respectively, whichcommunicate with the clutch mechanisms. The control element is broughtto this position by movement of the indicating handle I83 (Figs. 10 and20) into the position marked I, 2, 3, with the resulting rotation ofshaft I88 and control element I40 to the position shown in Figs. 10,12A, 20, and2l. At the same time the cam I34 which is actuated by shaftI38 is in the position shown in Fig. 11 in which the slide I82 is heldin its retracted or right hand position as shown in Fig. 1 against theaction of spring I84 and the one way clutch devices associated withshafts I4 and 24 are rendered operative. e

To provide a neutral position, setting lever I88 is moved to theposition designated neutral in Figs. 10 and 20 whereupon the valve I40will take the position shown in Fig. 123 wherein all communication fromconduits I and I2 within conduits I0 and 12 is prevented.

when it is desired to use the extra low gear ratio which, as describedabove, is effected by shifting thegear teeth I26 into engagement withthe gears I28 within housing I6, the indicating handle I83 is rotated tothe central position shown in Figs. and with the result that the controlmember I40 is rotated to the position shown in Fig. and in Fig. 120 andcam I34 is rotated by shaft I38 to permit the slide I32 to move to theleft as seen in Fig. 1 under the action of spring I84, and theprojections H6 and H6 serve to render the one way clutch devicesinoperative. The valve I12 is then allowed to move to the-low gearposition of Fig. '22. The resulting pressure in line 12' which normallycommunicates with the conduit 12 is now communicated instead to theconduit 10 so that while the valve slide is in the position shown inFig. 22,

oil for actuating the clutch C is passed from the pressure line 12'through apassage I86 in the control member to the conduit 10. v

In order to drive the power output shaft in reverse, the indicatinghandle I82 is moved into the extreme right hand position so as to rotatethe control element'l40 to the position shown in Fig. 26 and in Fig. 12Dwhile the cam I34 still permits the slide I32 to remain in the left handposition. Upon movement'of valve I12 to the low gear position (Fig. 22)oil under pressure is then supplied from conduit 12' to the conduit 12for actuating clutch D through the passage I85 in control element I40.

While the mechanism is in either the low-low gear ratio or reverse, thevalve I12 is prevented from rising above the position of Fig. 22, saidcontrol being eflected by the rotation of control element I40. This maybe accomplished by means of a pin I88 (Figs. 10, 13 and 22) which ismoved into a slot I88 inthe valve by means of a cam I80 carried by ormovable with the element I40. Normally, the pin I88 is held retracted.

to any of its various positions. However, when the arm I82 is moved toeither the low-low positionor to reverse, the shaft I88 is rotatedcausing cam I90 to move pin I88 into slot I88 so that while the valvecan be moved downward to the neutral position of Figs. 10 and 21 itcannot rise above the position of Fig. 22 in which it is located whenthe mechanism is operating in low, low-low, or reverse.

The means employed for moving valve I12 up and down to eifect thecontrol of the clutch members may be of any suitable design andcharacter. However, as shown in Figs. 10and 20 the valve may be urgedupwardly by a 'spring 200 located in a chamber 202 beneath the valve.The chamber 202 which serves as a dashpot may be formed with a passage204 near the bottom thereof which communicates with a relatively largecheck valve controlled passage 208 opening into an open top oilreservoir 208 which is supplied with oil as by drainage through opening208' (Fig. 10). When the valve H2 is depressed, oil flows freely frombeneath the valve through the passage 208, past the ball 2I0 into thereservoir 208 and a part thereof may overflow into the transmissionhousing. A second smaller passage 2I2 extends from reservoir 208 to thepassage 204 so that oil may flow slowly back into the chamber 202 whenthe spring urges, the valve upward. The rate of flow of oil through thepassage 2I2 may be regu-v lated as necessary by means of the adjustingscrew 2I4. A passage-2I8 may also be provided communicating with thespace 2I8 above the valve to permit oil to flow into and out of saidspace as the valve moves up and down. Space 2I8 may be closed by meansof a bellows 2I8 of suitable material.

The valve may be moved downward against the action of spring 200 by ahand lever 220, shown in Fig. 20, which serves to raise the right handend of the pivoted arm 222 and depress the left hand end thereof towhich the valve I12 is connected. A spring biased lost motion connectionis provided between the bell crank 224 connected to hand lever 220 andthe pivoted arm 222. The construction embodies a spring 220 which iscompressed by movement of thelever 220 to the left as shown in Fig. 20whereby the spring serves to force the link 228 and the right hand andof the pivoted arm 222 downward to raise the left hand end thereof withthe valve I12. The hand lever may be set for any desired gear ratio by acatch 280 engaging a rack segment 232 so as to hold the mechanism inneutral, low, or intermediate speed if necessary.

A footpedal 234 may be used in place of or supplemental to the handlever 220 for operating the valve I12. Preferably connected for movementwith the lever 222 and foot pedal 284, is a segment 2221 having asuitable number of depressions 222z'therein receiving a spring presseddetent 2223 to permit the operator to more readily keep the valve I12 inone of its definite positions of adjustment.

In case. it is desired to adjust the mechanism to direct gear when theengine is not running as vided to prevent oil passing back through thepressure lines 10' and 12'. It is also necessary to provide check valves248 in the lines 250 extending from the hand pump 244 to the conduits Iintermediate members, means for connecting atv and I2 to prevent loss ofoil pressure by flow outward therethrough during normal operationof themechanism. Oil under pressure may therefore be supplied at will tooperate the clutch mechanism when the pump I62 is not operating.

If desired the mechanism may be actuated by any suitable automaticcontrol device such as that shown and described in my copendingapplication Serial No. 747,833 filed October 11, 1934. Such a device isindicated generally at 240 in Fig. and is supplied with oil underpressure from the pump. I62 through the line 242 for operating the same,a.shut ofi valve 242' being furnished, if desired, to disable theautomatic control device. Said device will, of course, include somepressure controlled device acting upon the valve I12 as by pressingagainst the right end of the segment 2221 of Fig. 20.

The operation of the valve operating mechanism will be apparent from theforegoing description thereof. The valve I I2 is moved intoneutralposition as shown in Figs. 10 and 21 by means of the hand lever220, the foot pedal 234 or other suitable control device. If the handlever 220 and its'associated parts are used the spring 226 is made ofsuch strength and the parts are so proportioned that it can overcome theeffect of spring 200 when the lever is in the position shown in Fig. 20but when in'one of the other positions spring 200 can move the valve I12to the corresponding position. Upon release of the foot pedal when thehand lever is set to the position I (Fig. 20) the spring 200 may forcethe valve I12 upwardly. However, the dashpot construction at the bottomof valve II2 (Fig. 10) renders the upward movement as slow as desired sothat the device passes gradually from neutral to low, low tointermediate and then to direct with suflicient delay between thetransition from one to the other to allow the parts to attain thenecessary speed to prevent overloading or stalling of the motor. By thismeans a semi-automatic operation is made possible in that the only actrequired of the operator in starting the car forward is the release(sudden, if desired) of the foot pedal 234, whereupon the transmissionwill be gradually adjusted for low, intermediate and "direct withoutfurther attention. of valve movement is, of course, so adjusted that themotor can under normalconditions (as on level ground) accelerate the carsufficiently during the time. the transmission is in low or intermediategear ratio to be able to accelerate the car further in the next higherratio.

It will be noted that the change over from one ratio to another occurswithout interrupting the flow of power from the motor to the drivewheels of the car to which the shaft B is of course connected.

While the automatic transmission heretofore described is shown inassociation with an automobile, it will be understood that the same isadapted for other uses and purposes; and while, for the sake ofclearness, only certain expressions of the inventive idea have beenillustrated and described in detail, it is to be understood that theinvention is not limited thereto, but that the inventive idea issusceptible of various mechanical expressions within the limits of theappended claims, and that certain features thereof may be used alone orin combination with other known or suitable devices.

What is claimed is:

1. In an energy transmission device, a power input member and a poweroutput member, two

The rate will either or both of said intermediate members to said powerinput member, a sun gear connected to one of said intermediate members,a second sun gear connected to said output member, a planetary armconnected for operation by said other intermediate member andservingtocarry three connected planetary gears two of which mesh respectivelywith said sun gears and the third of which meshes with a stationarysungear and means for disengaging said stationary sun gear from itsplanetary gear.

2. In, an energy transmission device, a power input member and a poweroutput member, two intermediate members, means f orconnecting at willeither or both of said intermediate members to said power" input member,a sun gear connected to one of said intermediate members, a second sungear connected to said output member, a planetary arm connected foroperation by said other intermediate-member and serving to carry threeconnected planetary gearsstwo of which mesh respectively with'said sungears and the third of which meshes with a stationary sun gear and meansfor freeing said third planetary gear from the control of saidstationary sun gear.

3. An energy transmissiondevice comprising a power input shaft, a poweroutput shaft, a plurality of alternatively operable connections betweensaid input and output'shafts and selectively operable, andhydraulicallyactuated means for effecting the desired connection betweensaid input and output shafts comprising a-- source of fluid pressure anda valve for connecting said source at will with either, or both of saidhydraulically actuated means, a second valve or modifying the efiect ofsaid first mentioned means and means made effective as an incident tothe setting of said second valve to control the extent of movement ofsaid first mentioned valve.

4. In an energy transmission device, a power input member and a poweroutput member, two intermediate members, means for connecting at willeither or both of said intermediate members to said power input member,a sun gear connected to one of said intermediate members, a second sungear connected to said output member, a planetary arm connected foroperation by said other intermediate member and serving to carry threeconnected planetary gears two of which mesh respectively with said sungears and the third of which meshes with a stationary sun gear and meansfordisengaging said stationary sun gear from its planetary gear, meansnormally preventing reverse rotation of said intermediate members andmeans for disabling said preventing means when said stationary sun gearis engaged with said third planetary gear.

5. An energy transmission device'comprising a rotatably mounted powerinput member, a

power output member, an intermediate shaft having means at one end forclutching it at will to said power input member and connected at theother end to an arm member of a planetary gearing, an intermediatetubular member surrounding said intermediate shaft and having means atone end for clutching it at will to said power input member andconnected at its other end to a sungear of said planetary gearing, twoplanetary gears connected together and carried by said planetary arm,one of said planetary gears meshing wit said sun gear and the othermeshing with a s gear on the power output member.

6. The combination set forth in claim 5 together with means effective atwill for preventing reverse rotation of said planetary arm and/or saidtubular member.

'1. The combination set forth in claim 5 toreverse rotation of saidplanetary arm and/or said tubular member, and means for at will makf aing either or both of said clutching means efiective.

8. An energy transmission device comprising a rotatably mounted powerinput member, a power output member, a planetary gearing comprising aplanetary arm, two connected gears carried thereby and two sun gearsmeshing with said planetary gears, an intermediate shaft having means atone end for clutching it at will to said power input member, anintermediate tubular aim member surrounding said intermediate shaft andhaving means at one end for clutching it at will to said power inputmember, one of said sun gears being connected with said power outputmember and the other sun gear for rotation with one of said intermediatemembers and the planetary arm being connected for rotation with theother intermediate member. 9. The combination set forth in claim 8 together with means for at will making either or both of said clutchingmeans eflective.

10. The combination set forth-in claim 5 together with means for at willmaking either or both of said clutching means effective.

I HANS THOMA.

